This invention relates to apparatus for feeding lumber or the like and more particularly to improved apparatus for feeding pieces of lumber of various thicknesses and widths arranged in side-by-side relationship relative to each other along a path with the center lines of the pieces extending substantially on a preselected datum plane in the direction of movement of the lumber or the like.
Heretofore in the art to which my invention relates, various types of apparatus have been proposed for feeding pieces of lumber to other apparatus for finishing the same. Such finishing apparatus usually employs opposing sanding belts or rotating cutter heads on opposite sides of the path along which the pieces of lumber or the like are conveyed. The sanding belts or cutter heads operate to remove substantially equal amounts of material from opposite sides of the board being finished. Accordingly, it is very desirable to maintain the longitudinal center line of the board midway between the opposing sanding belts or cutter heads since the spacing therebetween determines the final thickness of the lumber.
Conventional apparatus, with which I am familiar, heretofore used to convey pieces of lumber or the like for further finishing operations employed endless chain drive units which engage the lumber being conveyed. Such prior art apparatus requires complicated hydraulic and/or mechanical biasing mechanisms to move the lumber engaging chains equal distances relative to opposite sides of the datum plane to thus maintain the center line of the boards being conveyed on the datum plane. With some prior art conveying apparatus such as shown in U.S. Pat. No. 3,915,290, the individual links of the conveying chain actually engage the pieces of lumber being conveyed. This results in considerable wear of the chain links at the point of contact with the lumber. Accordingly, proper engagement of the chain links with the pieces of lumber being conveyed and efficient movement of such pieces into and through the finishing apparatus is significantly impaired. Also, considerable time and effort is required with such apparatus to maintain it in proper operating order.
Other conventional lumber feeders employing endless chain drive units to convey pieces of lumber or the like along a path are illustrated in the following U.S. Pat. Nos. 1,746,697; 1,911,961; 2,387,446; 2,546,476; 3,143,269; 3,258,110; 3,386,565; and 3,847,271.